1 /*
2  * wm831x-isink.c  --  Current sink driver for the WM831x series
3  *
4  * Copyright 2009 Wolfson Microelectronics PLC.
5  *
6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7  *
8  *  This program is free software; you can redistribute  it and/or modify it
9  *  under  the terms of  the GNU General  Public License as published by the
10  *  Free Software Foundation;  either version 2 of the  License, or (at your
11  *  option) any later version.
12  */
13 
14 #include <linux/module.h>
15 #include <linux/moduleparam.h>
16 #include <linux/init.h>
17 #include <linux/bitops.h>
18 #include <linux/err.h>
19 #include <linux/i2c.h>
20 #include <linux/platform_device.h>
21 #include <linux/regulator/driver.h>
22 #include <linux/slab.h>
23 
24 #include <linux/mfd/wm831x/core.h>
25 #include <linux/mfd/wm831x/regulator.h>
26 #include <linux/mfd/wm831x/pdata.h>
27 
28 #define WM831X_ISINK_MAX_NAME 7
29 
30 struct wm831x_isink {
31 	char name[WM831X_ISINK_MAX_NAME];
32 	struct regulator_desc desc;
33 	int reg;
34 	struct wm831x *wm831x;
35 	struct regulator_dev *regulator;
36 };
37 
38 static int wm831x_isink_enable(struct regulator_dev *rdev)
39 {
40 	struct wm831x_isink *isink = rdev_get_drvdata(rdev);
41 	struct wm831x *wm831x = isink->wm831x;
42 	int ret;
43 
44 	/* We have a two stage enable: first start the ISINK... */
45 	ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA,
46 			      WM831X_CS1_ENA);
47 	if (ret != 0)
48 		return ret;
49 
50 	/* ...then enable drive */
51 	ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE,
52 			      WM831X_CS1_DRIVE);
53 	if (ret != 0)
54 		wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0);
55 
56 	return ret;
57 
58 }
59 
60 static int wm831x_isink_disable(struct regulator_dev *rdev)
61 {
62 	struct wm831x_isink *isink = rdev_get_drvdata(rdev);
63 	struct wm831x *wm831x = isink->wm831x;
64 	int ret;
65 
66 	ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE, 0);
67 	if (ret < 0)
68 		return ret;
69 
70 	ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0);
71 	if (ret < 0)
72 		return ret;
73 
74 	return ret;
75 
76 }
77 
78 static int wm831x_isink_is_enabled(struct regulator_dev *rdev)
79 {
80 	struct wm831x_isink *isink = rdev_get_drvdata(rdev);
81 	struct wm831x *wm831x = isink->wm831x;
82 	int ret;
83 
84 	ret = wm831x_reg_read(wm831x, isink->reg);
85 	if (ret < 0)
86 		return ret;
87 
88 	if ((ret & (WM831X_CS1_ENA | WM831X_CS1_DRIVE)) ==
89 	    (WM831X_CS1_ENA | WM831X_CS1_DRIVE))
90 		return 1;
91 	else
92 		return 0;
93 }
94 
95 static int wm831x_isink_set_current(struct regulator_dev *rdev,
96 				    int min_uA, int max_uA)
97 {
98 	struct wm831x_isink *isink = rdev_get_drvdata(rdev);
99 	struct wm831x *wm831x = isink->wm831x;
100 	int ret, i;
101 
102 	for (i = 0; i < ARRAY_SIZE(wm831x_isinkv_values); i++) {
103 		int val = wm831x_isinkv_values[i];
104 		if (min_uA <= val && val <= max_uA) {
105 			ret = wm831x_set_bits(wm831x, isink->reg,
106 					      WM831X_CS1_ISEL_MASK, i);
107 			return ret;
108 		}
109 	}
110 
111 	return -EINVAL;
112 }
113 
114 static int wm831x_isink_get_current(struct regulator_dev *rdev)
115 {
116 	struct wm831x_isink *isink = rdev_get_drvdata(rdev);
117 	struct wm831x *wm831x = isink->wm831x;
118 	int ret;
119 
120 	ret = wm831x_reg_read(wm831x, isink->reg);
121 	if (ret < 0)
122 		return ret;
123 
124 	ret &= WM831X_CS1_ISEL_MASK;
125 	if (ret > WM831X_ISINK_MAX_ISEL)
126 		ret = WM831X_ISINK_MAX_ISEL;
127 
128 	return wm831x_isinkv_values[ret];
129 }
130 
131 static struct regulator_ops wm831x_isink_ops = {
132 	.is_enabled = wm831x_isink_is_enabled,
133 	.enable = wm831x_isink_enable,
134 	.disable = wm831x_isink_disable,
135 	.set_current_limit = wm831x_isink_set_current,
136 	.get_current_limit = wm831x_isink_get_current,
137 };
138 
139 static irqreturn_t wm831x_isink_irq(int irq, void *data)
140 {
141 	struct wm831x_isink *isink = data;
142 
143 	regulator_notifier_call_chain(isink->regulator,
144 				      REGULATOR_EVENT_OVER_CURRENT,
145 				      NULL);
146 
147 	return IRQ_HANDLED;
148 }
149 
150 
151 static int wm831x_isink_probe(struct platform_device *pdev)
152 {
153 	struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
154 	struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
155 	struct wm831x_isink *isink;
156 	int id = pdev->id % ARRAY_SIZE(pdata->isink);
157 	struct regulator_config config = { };
158 	struct resource *res;
159 	int ret, irq;
160 
161 	dev_dbg(&pdev->dev, "Probing ISINK%d\n", id + 1);
162 
163 	if (pdata == NULL || pdata->isink[id] == NULL)
164 		return -ENODEV;
165 
166 	isink = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_isink),
167 			     GFP_KERNEL);
168 	if (isink == NULL) {
169 		dev_err(&pdev->dev, "Unable to allocate private data\n");
170 		return -ENOMEM;
171 	}
172 
173 	isink->wm831x = wm831x;
174 
175 	res = platform_get_resource(pdev, IORESOURCE_REG, 0);
176 	if (res == NULL) {
177 		dev_err(&pdev->dev, "No REG resource\n");
178 		ret = -EINVAL;
179 		goto err;
180 	}
181 	isink->reg = res->start;
182 
183 	/* For current parts this is correct; probably need to revisit
184 	 * in future.
185 	 */
186 	snprintf(isink->name, sizeof(isink->name), "ISINK%d", id + 1);
187 	isink->desc.name = isink->name;
188 	isink->desc.id = id;
189 	isink->desc.ops = &wm831x_isink_ops;
190 	isink->desc.type = REGULATOR_CURRENT;
191 	isink->desc.owner = THIS_MODULE;
192 
193 	config.dev = pdev->dev.parent;
194 	config.init_data = pdata->isink[id];
195 	config.driver_data = isink;
196 
197 	isink->regulator = regulator_register(&isink->desc, &config);
198 	if (IS_ERR(isink->regulator)) {
199 		ret = PTR_ERR(isink->regulator);
200 		dev_err(wm831x->dev, "Failed to register ISINK%d: %d\n",
201 			id + 1, ret);
202 		goto err;
203 	}
204 
205 	irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0));
206 	ret = request_threaded_irq(irq, NULL, wm831x_isink_irq,
207 				   IRQF_TRIGGER_RISING, isink->name, isink);
208 	if (ret != 0) {
209 		dev_err(&pdev->dev, "Failed to request ISINK IRQ %d: %d\n",
210 			irq, ret);
211 		goto err_regulator;
212 	}
213 
214 	platform_set_drvdata(pdev, isink);
215 
216 	return 0;
217 
218 err_regulator:
219 	regulator_unregister(isink->regulator);
220 err:
221 	return ret;
222 }
223 
224 static int wm831x_isink_remove(struct platform_device *pdev)
225 {
226 	struct wm831x_isink *isink = platform_get_drvdata(pdev);
227 
228 	free_irq(wm831x_irq(isink->wm831x, platform_get_irq(pdev, 0)), isink);
229 
230 	regulator_unregister(isink->regulator);
231 
232 	return 0;
233 }
234 
235 static struct platform_driver wm831x_isink_driver = {
236 	.probe = wm831x_isink_probe,
237 	.remove = wm831x_isink_remove,
238 	.driver		= {
239 		.name	= "wm831x-isink",
240 		.owner	= THIS_MODULE,
241 	},
242 };
243 
244 static int __init wm831x_isink_init(void)
245 {
246 	int ret;
247 	ret = platform_driver_register(&wm831x_isink_driver);
248 	if (ret != 0)
249 		pr_err("Failed to register WM831x ISINK driver: %d\n", ret);
250 
251 	return ret;
252 }
253 subsys_initcall(wm831x_isink_init);
254 
255 static void __exit wm831x_isink_exit(void)
256 {
257 	platform_driver_unregister(&wm831x_isink_driver);
258 }
259 module_exit(wm831x_isink_exit);
260 
261 /* Module information */
262 MODULE_AUTHOR("Mark Brown");
263 MODULE_DESCRIPTION("WM831x current sink driver");
264 MODULE_LICENSE("GPL");
265 MODULE_ALIAS("platform:wm831x-isink");
266